The present invention is directed to electrical circuits and techniques thereof.
Linear amplifiers have a wide range of applications. Typically, linear amplification refers to the ability to have an output linearly proportional to an input. Among linear amplifiers, cascode based designs have been a popular choice. Compared to single stage amplifiers, cascode amplifiers often offer a high level of isolation, high input impedance, high gain, and high bandwidth. Since its invention in early 1900s, various versions of cascode amplifiers have been proposed and used, including vacuum tube and transistor implementations. In transistor implementations, both bipolar junction transistors (BJT) and field effect transistors (FET) can be used to implement cascode amplifiers.
Unfortunately, while there are many existing cascode amplifiers, they have been inadequate, as explained below. It is thus to be appreciated that new and improved amplifiers are desired.